工作记忆中的部分线索效应:任务呈现方式的影响

以往研究主要在长时记忆中考察部分线索效应,很少关注工作记忆中的部分线索效应及其作用机制。本研究采用项目再认任务,考察了工作记忆中提供部分学习项目作为提取线索,对存储在工作记忆中的已有表征的影响。结果发现：有、无部分线索试次分组呈现时,相较于无部分线索条件,有部分线索条件下再认正确率和d'降低,β升高,反应时间延长;有、无部分线索试次随机混合呈现时,有部分线索条件下再认正确率降低,β升高,但反应时间并无显著延长。结果表明：工作记忆中部分线索的提供降低了目标项目的表征强度;研究结果可用提取抑制假说解释,但工作记忆中部分线索的作用可能受注意资源有限性制约。     

工作记忆内容对无意视盲的改善作用

无意视盲是注意捕获失败的一种现象.研究发现:工作记忆内容对视觉注意的引导可以影响视觉注意的捕获.本研究以此为基础探讨了工作记忆内容能否影响无意视盲.本研究采用了静态无意视盲典型范式,通过两个实验分别探讨了工作记忆对无意视盲的引导作用以及在不同知觉负荷下引导作用的自动性,进而研究工作记忆内容对无意视盲的改善作用.实验1结果表明,当非期望刺激与工作记忆内容属于同一类别时,对非期望刺激的觉察率显著高于当非期望刺激与工作记忆内容不属于同一类别的情况,说明在纯语义的水平上工作记忆内容可以引导视觉注意捕获,进而改善无意视盲.实验2发现,当知觉负荷由低到高变化时,非期望刺激与工作记忆内容同类属时,觉察率无显著变化,说明工作记忆内容对无意视盲引导不受知觉负荷的调节,是一种自动化的过程.     

空间注意能够促进知觉表征进入工作记忆:来自注意瞬脱的证据

本研究目的一是探讨外周空间线索能否促进知觉表征进入工作记忆,二是观察线索的信息性对该促进作用时间进程的影响。实验采用注意瞬脱和空间线索结合的实验范式,考察不同信息性线索对目标识别的促进效应在注意瞬脱期间内外的变化。实验1和实验2分别采用了非信息性和信息性线索。结果显示：外周线索的促进效应在瞬脱期间内显著大于瞬脱期间外;非信息性线索和信息性线索分别在较短和较长的线索-目标间隔下起促进效应。因此,外周线索能促进知觉表征进入工作记忆,而不同信息性线索可能引发不同的注意机制．从而具有不同人促进效应。     

视觉工作记忆回溯线索效应的产生机制：认知阶段分离

以往研究关于视觉工作记忆回溯线索效应的产生机制主要存在5种假设, 目前依然存在争议。本研究通过改进前人研究实验范式, 采用包含内源性回溯线索的颜色回忆报告范式, 进一步对这5种假设进行检验。在实验1中, 我们调控了线索与探测阵列之间的时间间隔, 发现不同时间间隔不影响无线索条件的行为表现, 而在正常线索条件中被试的记忆精度以及能记住的项目数量均优于无线索条件; 在实验2中, 我们对回溯线索伴随的干扰刺激类型进行控制, 结果显示, 在不同条件下记忆精度不存在差别, 但当回溯线索伴随干扰刺激呈现时, 被试能记住的项目数量会被降低, 降低程度受干扰刺激的类型调制; 在实验3中, 我们对伴随回溯线索的干扰刺激的呈现时间进行控制, 发现虽然回溯线索效应仍然存在, 但干扰刺激的呈现时间不会影响效应程度。研究结果表明, 回溯线索的出现使得被试能够在决策加工前完成内部注意资源的再分配, 从而避免了同时进行这两种认知加工与记忆表征维持本身竞争认知资源。本研究为认知阶段分离假设提供了支持证据, 对解决回溯线索效应产生机制的争议以及理解内部注意与视觉工作记忆的关系有重要意义。     

返回抑制对工作记忆储存和目标维持的影响

将线索一靶子范式和N—Back变式结合,以工作记忆的记忆错误和侵入错误数为指标,探讨了返回抑制与工作记忆的储存和加工之间的关系,并对返回抑制的机制进行了深入探讨。结果表明,当记忆项目出现在线索化位置时,两种错误数均显著高于出现于非线索化位置的情况,但侵入错误的抑制效应只出现于长SOA条件。这揭示了返回抑制既影响工作记忆的储存又影响对任务目标的维持,也为返回抑制的注意说提供了新证据。     

知觉负载和线索位置对视觉选择性注意的影响

采用线索范式,以汉语双字词为材料,探讨了不同工作记忆负荷条件下知觉负载、线索位置对视觉选择性注意的影响.结果表明:(1)线索位置影响被试对目标的加工,前线索条件下被试对目标的加工更为精细;(2)知觉负载对选择性注意的影响受到工作记忆的调节.高工作记忆负荷条件下,高知觉负载条件下的反应时显著短于低知觉负载条件;而在低工作记忆负荷条件下,不同知觉负载条件下的反应时差异不显著.     

连续报告任务中无效后线索对后线索效益的影响

本文采用连续报告任务,从非线索指示项目的角度入手,探讨无效后线索的存在是否会影响后线索效应的产生,以此进一步了解“后线索效益”的产生机制。结果表明,无论采用空间后注意线索,还是非空间的颜色后注意线索,都产生了“后线索效益”,即后线索确实提高了被试视觉工作记忆的表现。无效后线索的存在不会影响“后线索效益”的产生,该效益的理论解释符合优先提取说,即被试会利用后注意线索优先提取线索指示项目,产生更快和更准确的反应。     

部分线索对记忆提取的影响:认知抑制能力的作用

在回忆时,以刚刚学过的部分项目作为提取线索,被试的回忆成绩反而比没有任何线索时的回忆成绩差,这一现象被称为部分线索效应。该效应通常被认为是抑制执行控制过程对非线索项目记忆表征强度抑制的结果。本研究以Stroop效应量(实验1)和工作记忆容量(实验2)为指标,从个体差异角度考察了认知抑制能力对部分线索效应的影响。结果发现,Stroop效应量与部分线索效应各指标呈显著负相关,Stroop效应量越小,部分线索效应各指标的值越大;工作记忆容量与部分线索效应各指标呈显著正相关,高工作记忆容量个体的部分线索效应各指标的值也更大。结果表明,认知抑制能力越强,部分线索对回忆的破坏作用越大,研究结果支持部分线索效应的提取抑制假说。     

变化盲视的最新研究进展

变化盲视指观察者不能探测到客体或情境中的变化 ,是近十年以来认知心理学的研究热点之一。变化盲视可发生在各种实验条件下。例如 ,在扫视、眨眼、电影镜头切换时发生的变化以及真实情景的交互作用中发生的变化 ,观察者都有可能探测不到。本文介绍了近年来对于变化盲视的研究成果 ,包括经常使用的实验范式和对这个现象的解释等     

线索-反应相容性效应和线索有效概率的影响

运用前置线索技术,考察了线索－反应的相容性效应,研究了不同线索与反应的关系和线索有效概率对视觉剌激进行命名反应的时间的影响。结果表明：线索－反应的相容性存在,且符合维度重合理论,支持了相容性是信息加工过程的基本特征;线索客观有效概率影响了线索－反应的相容性效应的强度,线索客观有效概率越高,线索－反应的相容性效应越强。     

Working memory and inattentional blindness

Individual differences in working memory predict many aspects of cognitive performance, especially for tasks that demand focused attention. One negative consequence of focused attention is inattentional blindness, the failure to notice unexpected objects when attention is engaged elsewhere. Yet, the relationship between individual differences in working memory and inattentional blindness is unclear; some studies have found that higher working memory capacity is associated with greater noticing, but others have found no direct association. Given the theoretical and practical significance of such individual differences, more definitive tests are needed. In two studies with large samples, we tested the relationship between multiple working memory measures and inattentional blindness. Individual differences in working memory predicted the ability to perform an attention-demanding tracking task, but did not predict the likelihood of noticing an unexpected object present during the task. We discuss the reasons why we might not expect such individual differences in noticing and why other studies may have found them.     

Automatic and strategic effects in the guidance of attention by working memory representations

Theories of visual attention suggest that working memory representations automatically guide attention toward memory-matching objects. Some empirical tests of this prediction have produced results consistent with working memory automatically guiding attention. However, others have shown that individuals can strategically control whether working memory representations guide visual attention. Previous studies have not independently measured automatic and strategic contributions to the interactions between working memory and attention. In this study, we used a classic manipulation of the probability of valid, neutral, and invalid cues to tease apart the nature of such interactions. This framework utilizes measures of reaction time (RT) to quantify the costs and benefits of attending to memory-matching items and infer the relative magnitudes of automatic and strategic effects. We found both costs and benefits even when the memory-matching item was no more likely to be the target than other items, indicating an automatic component of attentional guidance. However, the costs and benefits essentially doubled as the probability of a trial with a valid cue increased from 20% to 80%, demonstrating a potent strategic effect. We also show that the instructions given to participants led to a significant change in guidance distinct from the actual probability of events during the experiment. Together, these findings demonstrate that the influence of working memory representations on attention is driven by both automatic and strategic interactions.     

Failures of retrieval and comparison constrain change detection in natural scenes

In a change detection paradigm, a target object in a natural scene either rotated in depth, was replaced by another object token, or remained the same. Change detection performance was reliably higher when a target postcue allowed participants to restrict retrieval and comparison processes to the target object (Experiment 1). Change detection performance remained excellent when the target object was not attended at change (Experiment 2) and when a concurrent verbal working memory load minimized the possibility of verbal encoding (Experiment 3). Together, these data demonstrate that visual representations accumulate in memory from attended objects as the eyes and attention are oriented within a scene and that change blindness derives, at least in part, from retrieval and comparison failure.     

Beyond heritability: neurotransmitter genes differentially modulate visuospatial attention and working memory

A cued, visuospatial attention task and a working memory task were administered to 89 healthy adults genotyped for a T-to-C polymorphism in CHRNA4, a nicotinic receptor subunit gene. Increasing gene dose of the C allele of the CHRNA4 gene (i.e., no C alleles, one C allele, two C alleles) was associated with increased reaction time (RT) benefits of valid attentional cuing and reduced RT costs of invalid cues, but was not associated with working memory performance. In a second experiment, 103 healthy persons were genotyped for a G-to-A polymorphism of the dopamine beta-hydroxylase (DBH) gene. Increasing gene dose of the G allele of the DBH gene was associated with increased working memory accuracy at a high memory load. However, there was no consistent association between the DBH gene and visuospatial attention. Thus, a double dissociation was observed, with visuospatial attention associated with CHRNA4 but not the DBH gene and, conversely, working memory associated with the DBH gene but not CHRNA4. The results show that normal allelic variations in single neurotransmitter genes modulate individual differences in processing components of cognitive functions in healthy individuals.     

Release of inattentional blindness by high working memory load: elucidating the relationship between working memory and selective attention

An unexpected stimulus often remains unnoticed if attention is focused elsewhere. This inattentional blindness has been shown to be increased under conditions of high memory load. Here we show that increasing working memory load can also have the opposite effect of reducing inattentional blindness (i.e., improving stimulus detection) if stimulus detection is competing for attention with a concurrent visual task. Participants were required to judge which of two lines was the longer while holding in working memory either one digit (low load) or six digits (high load). An unexpected visual stimulus was presented once alongside the line judgment task. Detection of the unexpected stimulus was significantly improved under conditions of higher working memory load. This improvement in performance prompts the striking conclusion that an effect of cognitive load is to increase attentional spread, thereby enhancing our ability to detect perceptual stimuli to which we would normally be inattentionally blind under less taxing cognitive conditions. We discuss the implications of these findings for our understanding of the relationship between working memory and selective attention.     

Trade-offs between gaze and working memory use

Eye movements during natural tasks suggest that observers do not use working memory to capacity but instead use eye movements to acquire relevant information immediately before needed. Results here however, show that this strategy is sensitive to memory load and to observers' expectations about what information will be relevant. Depending upon the predictability of what object features would be needed in a brick sorting task, subjects spontaneously modulated the order in which they sampled and stored visual information using working memory more when the task was predictable and reverting to a just-in-time strategy when the task was unpredictable and the memory load was higher. This self organization was evidenced by subjects' sequence of eye movements and also their sorting decisions following missed feature changes. These results reveal that attentional selection, fixations, and use of working memory reflect a dynamic optimization with respect to a set of constraints, such as task predictablity and memory load. They also reveal that change blindness depends critically on the local task context, by virtue of its influence on the information selected for storage in working memory.     

Cognitive Control of Attentional Guidance by Visual and Verbal Working Memory Representations

Both visual and verbal information in working memory guide visual attention toward a memory‐matching object. We tested whether: (a) visual and verbal representations have different effects on the deployment of attention; and (b) both types of representations can be used equally in a top‐down manner. We asked participants to maintain a visual cue or a verbal cue at the beginning of each trial, and ended with a memory task to ensure that each cue was represented actively in working memory. Before the memory task, a visual search task appeared where validity was manipulated as valid, neutral, or invalid. We also manipulated the probability of valid trials (20%, 50%, and 80%), which had been told to the participants prior to the task. Consistent with earlier findings, attentional guidance by visual representations was modulated by the probability. We also found that this was true for verbal representations, and that these effects did not differ between representation types. These results suggest that both visual and verbal representations in working memory can be used strategically to control attentional guidance.     

驾驶员在交通场景中的变化视盲及其启示

变化视盲(change blindness)现象,也称变化盲,是指视觉情景中人们不能觉察到某个事物变化的现象。研究以驾驶员为主体探讨了道路交通领域中的变化视盲现象。首先,从场景变化特征和驾驶员特征两个方面综述了影响驾驶员变化视盲的影响因素;其次,结合影响因素与变化视盲的特征理论建立了驾驶员变化检测的认知过程模型;最后,在模型的基础上,讨论了提高驾驶员变化检测能力的实际意义和潜在措施,并对未来有关交通安全变化视盲的研究予以展望。     

视觉工作记忆内容对视觉搜索的影响

采用记忆任务与视觉搜索任务相结合的范式,以二维对称图形为材料,探讨视觉工作记忆内容对视觉搜索的影响。结果发现：（1）不同视觉工作记忆内容条件下的反应时存在显著差异,无效信息条件下的反应时显著长于有效信息条件下的反应时。（2）不同搜索序列条件下反应时差异显著,复杂序列条件下的反应时显著长于简单序列条件。结果表明,视觉工作记忆中的信息内容影响视觉搜索效率,其变化趋势不受序列大小的影响,结果支持偏向竞争模型。     

Limitations for Change Detection in Multiple Gabor Targets

We investigate the limitations on the ability to detect when a target has changed, using Gabor targets as simple quantifiable stimuli. Using a partial report technique to equalize response variables, we show that the log of the Weber fraction for detecting a spatial frequency change is proportional to the log of the number of targets, with a set-size effect that is greater than that reported for visual search. This is not a simple perceptual limitation, because pre-cueing a single target out of four restores performance to the level found when only one target is present. It is argued that the primary limitation on performance is the division of attention across multiple targets, rather than decay within visual memory. However in a simplified change detection experiment without cueing, where only one target of the set changed, not only was the set-size effect still larger, but it was greater at 2000 msec ISI than at 250 msec ISI, indicating a possible memory component. The steepness of the set-size effects obtained suggests that even moderate complexity of a stimulus in terms of number of component objects can overload attentional processes, suggesting a possible low-level mechanism for change blindness.